Chevrolet Runs for Hours then Sputters and Stops, NO Codes
Hey All, I am a mail carrier and have an unusual problem that I have not seen addressed anywhere else on the internet. On a cool temperature day, my blazer will run my 6 hour route with no problems whatsoever. However, on a hot day, after about 1 to 2 hours, my fuel pump starts whining really loudly. Then, after about another hour, the blazer will sputter and shut off, whether I am pressing the gas or coming to a stop at someone's mailbox. I have replaced the fuel pump, fuel filter, fuel pump relay, radiator, distributor cap, idle air control module, thermostat, throttle body module sensor... have had the catalytic converter rodded out.... heavy duty fan cluth put in.... fuel pressure and fuel pump grounding test fine, even when whining (approx 57 to 59 on pressure).... WHEN it shuts off, sometimes it will crank right back up and run anywhere from 10 minutes to 45 minutes.... sometimes, it will have to sit about 5 minutes before I can get it to crank again.... BUT if I am riding down the road and NOT stopping for several minutes, it runs fine, NO problems... I have been told that SOMETHING is getting hot, but there is no way to put an extra fan in there to keep things cool... Have been through 6 mechanics, including 2 Chevrolet mechanics, NO CODES SHOWING UP.... Can anyone help???
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Or do you mean it will CRANK but the engine will not run like it normally would start when cranking?
Assuming your answer to #1 is No: the engine is being turned by the starter but won't fire and run...
You really need to find out if you have spark at the plugs when the thing won't start. If you had someone with you when it happens who could crank while you observe a spare plug with one of the spark wires on it lying on the metal surface to see if there's a hot blue spark, that would be great. You would want to pull off the spark plug wire in advance to be sure it's not stuck to the plug and can be pulled easily when you need to. And take a pair of thin gloves to insulate your hand while taking off the wire and putting it on the hot engine connected to a plug which you can observe during cranking. They also sell a fake plug thing that replaces a test plug and has a gap to observe the spark at some box stores for a few dollars. But just putting the plug wire on the metal should get a spark jumping from the connector inside to the metal.
If no spark, then I'd suggest the crankshaft position sensor. If you can isolate it and can carry water with you, you might try cooling it off with water dribbled over it to see if that speeds up the recovery for starting back up.
Your ignition uses a distributor and a pickup coil that senses the rotor to know when to pulse the spark. Do those go weak where they might have increased distance in the gap when the engine gets really hot? I am going by calls to a radio car repair guy who helped people fix problems long ago and there was a problem with a part inside the distributors.
I am wondering if your noisy fuel pump is a red herring distracting from an ignition problem.
2014 Malibu 2LT, 2015 Cruze 2LT,
It really is down to having to happen so someone can jump to the starter to see if that initiates cranking. Maybe the whining fuel pump is a symptom of low voltage or current--or a failing ground connection. It would be interesting to have a fused line from the fuel pump connector close to the tank to a hand voltmeter in the cabin to see what happens there when the whining starts.
Will it overheat and turn off if left idling on a hot day next to a building to block wind and just saturate the engine compartment with heat?
2014 Malibu 2LT, 2015 Cruze 2LT,